The present invention relates to the art of swivel joints. It finds particular application in conjunction with swivel joints for supporting swiveling lamp arms and will be described with particular reference thereto. It is to be appreciated, however, that the invention is also applicable to other pivotal connections and joints. The invention will find utility in pivotally connecting members for other purposes, including fluid carrying members, structural members for supporting decorative and functional appliances, such as shaving mirrors, candle sconces, personal computer accessories, and the like.
Heretofore, lamp swivels have commonly included two or three cylindrical members interconnected end to end and defining a wire receiving passage extending therethrough. Adjacent swivel members have abutting upper and lower bearing surfaces for rotational, sliding contact. For maximum stability and freedom from wobbling, the bearing surfaces extended to the outer periphery of the swivel members. A ferrule was normally extended from one of the members through an interior collar in the other and was crimped or swaged thereto. The force with which the ferrule was crimped determined the degree of frictional engagement between the bearing surfaces, hence, the freedom or resistance to rotational movement. By crimping the ferrule harder, a stiffer swivel was created; by crimping the ferrule more loosely, a more free turning swivel was formed.
Commonly, the swivel members had the same circular outer diameter such that the outer surfaces thereof formed a continuous cylinder. Because the bearing surfaces were pressed into such firm, frictional contact that the attached arms did not wobble, the mating of the bearing surfaces formed only a small annular ring or gap around the swivel.
During assembly, the tubular steel arms were brazed to swivel members. The ferrule of one member was swaged to the annular collar of the next connecting the members rotatably together. Thereafter, the swivel and arm assemblies were plated, e.g. brass or chrome plating. Plating is rarely done prior to assembly. The close tolerances of the mating surfaces required for smooth rotational movement would be disturbed. Masking the bearing surfaces before coating is labor intensive, hence, expensive. Further, the finish would become damaged in handling as the parts are crimped together or joint lubrication could seep onto the finish and mar it.
In a normal plating operation, the swivel and arm assemblies were dipped in acid or other etching and plating solutions. Sometimes a small amount of acid or other plating solutions would be trapped between the bearing surfaces of the two swivel members. After the plating was completed, the trapped acid or other etching solution would leak out from between the bearing surfaces and onto the plated surface of the swivel members. The acid and other etching solutions commonly discolored or otherwise adversely affected the plated surface.
Powder coatings have become stylish for analogous applications and are commonly requested. However, powder coating has heretofore been unavailable on swivel members. Powder coatings are relatively thick and bridge small gaps or cracks. If a swivel member were powder coated, the powder coating would form a continuous surface and bridge the annular gap at the peripheral interface between bearing surfaces of the two swivel members. When the two swivel members were rotated relative to each other, the brittle powder coating layer cracked or chipped adjacent the peripheral bearing surface interface or gap.
The present invention contemplates a new and improved swivel assembly which overcomes the above referenced plating and powder coating problems and others.